Safety latch for crane hook



' Ap'rilZl, 1970 .w. R. MCLAIN I 7 3,507,014

SAFETY LATCH FOR CRANE HOOK Filed July 25,- I968 INVE/V TOR. WILLIAM R. McLA/N A Horney United States Patent US. Cl. 24-241 1 Claim ABSTRACT OF THE DISCLOSURE The safety latch of the invention comprises a chain which is attached by one end to the shank of a lift hook at a point substantially opposite the bill of the hook. The free end of the chain carries an elongated, substantially arcuately shaped connecting member having a hookshaped end. The bill of the hook is provided with an opening adjacent the end thereof facing the hook shank. A rigid cross pin is provided in substantially the center of the bill opening extending transversely of the bill. The hook-end of the connecting member is adapted to detach ably engage the rigid cross pin to thereby maintain the chain extended across and closing the open throat of the hook between the shank and the bill.

The present invention relates generally to lift hooks of the type used with overhead cranes for lifting and transporting loads and, more particularly, to an improved safety latch for such lift hooks which is effective to close the throat of the hook and prevent accidental dislodgernent therefrom of lifting cables, slings, or the like by which the loads to be lifted and transported are suspended from the lift hook.

It is, accordingly, a primary object of my invention to provide an improved safety latch for a lift book which can be easily installed on presently existing lift hooks without weakening the lift hook in any manner.

Another object of the invention is to provide a safety latch for a lift hook as set forth by the above statement of object which includes positive, detachable retention means for securing the safety latch in operative latching position.

It is a more specialized object of my invention to provide a safety latch for a lift hook having a shank, a main load-supporting body portion, a bill, and a throat defined between and by said shank and said bill. The safety latch comprises a flexible chain having one end mounted on the lift hook shank at a point substantially opposite the bill of the lift hook; a connecting member carried by the opposite end of the chain, the connecting member having a substantially hook shape at one end; the bill of the lift hook having an opening adacent the end thereof facing the lift hook shank; and a rigid cross pin in substantially the center of the opening extending transversely of the lift hook bill; the hook-end of the connecting member being adapted to detachably engage the cross pin to thereby maintain the chain extended across the throat of the hook between the shank and the bill thereof.

These and other objects will become more apparent after referring to the following specification and attached drawing, in which:

FIGURE 1 is a side elevational view of a lift hook provided with the safety latch of the invention;

FIGURE 2 is a sectional view taken substantially along the line IIII of FIGURE 1;

FIGURE 3 is an elevational view of the connecting member of the safety latch of the invention; and

FIGURE 4 is an elevational view of a spool which may be used to modify a lift hook in accordance with the invention.

Referring more particularly to the drawing, reference numeral 2 designates generally a lift hook assembly having the safety latch of the invention incorporated therein. The hook 2 includes a shank 4, a main load-supporting body portion 6, and a bill 8 having a transverse hole 10 therethrough adjacent its end, and a rigid cross pin 12 disposed substantially in the center of the opening 10 extending transversely of the bill 8 of the hook opposite the shank 4. A throat 14 is defined between and by the bill 8 and the shank 4. The opening 10 does not have a weakening effect upon the lift hook 2 since the opening is remote from the main load-suporting body portion 6 of the hook. It will be noted that the opening 10 is in the bill 8 of the hook which is not affected by strain when a load is suspended from the hook.

A ring or collar 16 is circumferentially disposed on the shank 4 of the lift book 2. A chain 18 is fixedly connected to the collar 16 by one end and is adapted to be extended across the throat 14 of the book. The free end 20 of the chain 18 carries an elongated, arcuately shaped connecting member 22 which is formed with a hook 24 at one end. The chain is connected to the connecting member 22 at a point intermediate the ends of the latter.

In operation, the chain 18 is put into latching position by extending it across the throat 14 of the hook and placing the hook-end 24 of the connecting member 22 in detachable engagement with the rigid cross pin 12. To remove the chain 18 from latching position, the connecting member 22 is disengaged from the rigid cross pin 12, thus permitting the chain to hang free from the collar 16 clear of the throat 14.

I have found it preferable, when modifying existing lift hooks for the incorporation of my invention, to cut a transverse groove in the bill of the hook adjacent its end and then weld a steel spool 26, as shown in FIGURE 4, in the groove extending transversely of the bill. After the spool is welded in the groove of the bill, its projecting portions are cut and shaped to conform with the shape of the bill.

While I have shown but one embodiment of my invention, adaptations and modifications may be made without departing from the scope of the following claim.

I claim:

1. In a lift hook having a shank, a main load-supporting body portion, a bill, and a throat defined between and by said shank and said bill, the improvement therewith of a safety latch adapted to extend across said throat between said shank and said bill, safety latch comprising a flexible chain having one end mounted on said shank at a point substantially opposite said bill, a connecting member carried by the opposite end of said chain, said connecting member having a substantially hook shape at one end, said bill having an opening adjacent the end thereof facing said shank, a rigid cross pin in substantially the center of said opening extending transversely of said bill, said hook end of said connecting member being adapted to detachably engage said cross pin to thereby maintain said chain extended across the throat of said hook between said shank and said bill.

References Cited UNITED STATES PATENTS 950,641 3/1910 Sands 24-241 1,753,326 4/1930 Yingling 24-241 2,256,164 9/1941 Mahoney 24-241 ANDRES H. NIELSEN, Primary Examiner US. Cl. X.R. 294-78 

